2-Wire Ohms Function Offset Test - Agilent Technologies 3458A Calibration Manual

2-Wire Ohms
Function Offset Test
46 Chapter 4 Performance Verification Tests
done, turn the instrument ON and allow it to warm up before
proceeding.
3. The internal temperature of the 3458A under test must be within
5 degrees C of its temperature when last ohms adjusted. The current
internal temperature can be obtained by executing TEMP?. Compare
this temperature to adjustment temperature obtained by executing the
command CAL? 60 and record both temperatures on the OHMS
TESTS Test Card.
4. If the instrument self test has not been run, make certain all inputs are
disconnected and execute the TEST function. The display must read
"SELF TEST PASSED".
5. If you have just performed DCI tests, you have done an ACAL OHMS
which takes approximately ten minutes to complete. Compare the
TEMP? temperatures recorded on the DC CURRENT TESTS and
OHMS TESTS Test Cards. If they differ by more than 1
ACAL OHMS again. If DCI tests have not been done previously,
execute ACAL OHMS.
6. Configure the transfer standard DMM as follows:
-- OHMF
-- NDIG 8
-- NPLC 100
-- OCOMP ON
-- Trig SGL
7. Configure the DMM under test as follows:
-- OHM
-- NDIG 8
-- NPLC 100
-- OCOMP ON
-- Trig SGL
The following procedure performance verifies the front terminal ohms offset.
1. Connect a low thermal short across the front panel HI and LO input
terminals of the 3458A under test as shown in Figure 1.
Set the 3458A under test to the 10 W range. Allow 5 minutes for the
2.
range relays to thermally stabilize.
3. Execute Trig and use the OHMS TESTS Test Card to record the offset
reading.
4. Remove the short from the front panel input terminals.
°
C. execute